Electric socket



May 16, 1939. G. B. BENANDER ELECTRIC SOCKET Filed March 2 1936 Geo rge B.Bena1 wder:

49 ttorney.

I nverwtor- 7r His Patented May 16, 1939 UNITED STATES PATENT OFFICE Monowatt Electric Corporation,

Bridgeport,

Conn., a corporation of Connecticut Application March 25, 1936, Serial No. 70,778

23 Claims.

The present invention relates to electric sockets having provisions for preventing shortcircuit between the terminals of the socket when the socket is empty. One use of sockets of this type is for Christmas tree lights where the conventional socket is likely to be short-circulted by pieces oi tinfoil dropping between the terminals of the socket.

The object of my invention is to provide an improved construction for sockets of this type and for a consideration of what I believe to be novel in my invention, attention is directed to the accompanying description and the claims appended thereto.

In the accompanying drawing Fig. 1 is an elevation of a socket embodying my invention showing a lamp in the socket; Fig. 2 is a sectional elevation at right angles to Fig. l with one-half of the base removed and showing the lamp in the socket; Fig. 3 is a view similar to Fig. 2 with the lamp removed; Fig. 4 isa sectional view similar to Fig. 1 with the lamp removed; Fig. 5 is a sectional elevation of a modification with one-half of the base removed and a lamp in the socket: Fig. 6 is a view similar to Fig. 5 with the lamp removed; Fig. '1 is a sectional elevation of another modification with a lamp in the socket; Fig. 8 is a view similar to Fig. 7 with the lamp removed; Fig. 9 is a top plan view of the member for preventing contact with the center terminal of the socket when the lamp is removed; Fig. 10 is a sectional elevation of another modification showing a lamp in the socket; and Fig. 11 is a view similar to Fig. 10 with the lamp removed; Fig. 12 is a sectional elevation of another modiflcation with one-half of the base removed showing a lamp in the socket: and Fig. 13 is a view similar to Fig. 12 with the lamp'removed.

Referring to the drawing the numeral I indicates a screw shell which serves as one terminal for the socket. The shell is carried within a base which comprises parts 2 and 3 of molded insulating material which are held together by a U shaped spring clip 4 which fits in grooves 4a. The base is split along the axis of the shell so that the base may be assembled around the shell. One of the arms of the clip I is provided with a tang 5 and the other arm is provided with a rounded projection 50 which fit into depressions in the parts of the base and prevent easy removal 01' the clip. From the rounded projection Ila of the clip extends an arm 6 which cooperates with the base to provide a clip for supporting the socket. This clip is particularly useful in the case of sockets for use on Christmas trees since the clip 6 may be fastened over a branch of the tree.

At the lower end of the base the abutting surfaces of the parts of the base are provided with spaced transverse grooves l for clamping a pair of conductors 8 between the parts of the base. One of the conductors is connected to a contact 9 which serves as the center terminal of the socket. This contact is provided with tangs ll (see Fig. 4) which extend on either side of the conductor and are electrically connected thereto by squeezing the tangs together. The other conductor is similarly connected to a contact II which is adapted to engage the shell i which serves as the other terminal. of the socket. The tangs of the contact ll extend over both of the conductors but are electrically connected to only the lower conductor. With this arrangement the contact H serves to prevent displacement of the conductors. The conductors 8 are adapted to iorm the respective conductors of a string of parallel connected Christmas tree lights.

The center terminal 9 extends through an opening provided by complementary grooves I! in the parts 2 and 3 of the base into a recess I! in the base. The contact ll, likewise, extends into the recess i3 through complementary grooves l4 iormed in the parts 01 the base. The grooves l2 and it hold the contacts I and Ii in place.

The inner surface of the recess II is provided with threads II which cooperate with the thrads IE on the screw shell I. The friction between the threads l4 and i5 is such that the shell is threaded into and out of the base by a plug i6 threaded into the shell. That is, the fr tion between the threads of the plug it and the t eads of the shell is greater than the friction between the threads of the shell and the threads llof the base. The lower end of the shell I has a smooth portion l'l so that the shell cannot be treaded outward beyond the position shown in Fig. 3. The contact of the threads ll of the base with the smooth portion ll of the shell provides a stop which limits the outward movement. When the .shell is in the outer position, there is a wedging action between the threads I! and I5 which tends to separate the parts 2 and 3 of the base. The pressure exerted by the parts of the base on the shell holds the shell firmly in its outer position so that it will not be moved inward by jarring the socket. In the bottom of the shell is a diskshaped member IB of insulating material having an opening l9 therein for the center terminal 9 of the socket. The disk lBis held in place by spinning the shell against the outer edge of the disk. Beneath the disk l8 extends a flange 01' the shell which is adapted to make electrical contact with the contact Ii when the shell is threaded into the base. This contact is broken when the shell is threaded out of thebaseasshown in Fig. 3. When the shell is in the outer position, it is, therefore, electrically insulated from the conductors and the member it prevents contact with the center terminal 8 of metal particles such as tini'oil which fall into the shell. When the shell is in the outer position, it projects above the base but since it is electrically insulated when in this position there is no danger to the user.

Prior to inserting a lamp in the socket, the shell I is in the position shown in Fig. 3. In the use oi the socket the plug it of a lamp is threaded into the shell I. The plug is threaded into the shell until the friction between the threads on the plug exceeds the friction between the threads ii on the shell and the threads i4 on the base. As soon as this condition obtains the shell is threaded into the base without further threading oi the plug into the shell until the shell reaches the position shown in Fig. 1. In this position contact is made between the flange 24 on the shell and the contact H in the base and the center terminal 4 in the base projects into the opening IS in the insulating member ll. Further threading of the plug it causes the plug to be threaded into the shell to the position shown in Fig. 1. In this position the center contact 2! of the plug makes contact with the center termine] 9 of the base.

During the removal of the plug from the shell, the shell is first unthreaded from the base until it reaches the position shown in Fig. 3. This is due to the greater friction between the threads of the plug and the threads or the shell. After the shell reaches the position shown in Fig. 3, the plug is unthreaded from the shell to completely remove the plug from the socket.

The socket illustrated in Figs. 5 and 6 is identical in construction with the socket illustrated in Figs. 1 to 4, inclusive, except for the arrangement for limiting the outward movement 01' the shell. In this construction the smooth portion I1 01' the shell is omitted and tangs 22 are struck outwardly from the side walls oi the shell. These tangs extend within a recess 23 formed in the base and limit the outward movement or the shell by engaging stops provided by a shoulder 24 at the top of the recess.

The socket illustrated in Figs. 7, 8 and 9 has a base 25 of molded insulating material having a screw shell 26 secured therein. The screw shell is held in the base by a flange 21 at the upper edge of the shell which rrictionally engages the walls 28 of the base. At the lower end 0! the shell is flxed a disk 2! of insulating material having riveted thereto a contact 30 which serves as the center terminal oi the socket. Conductors ii are connected to the contact ill and conductors 32 are connected to the screw shell 26. The space between the conductors and the base is then filled with an insulating cement 83. The conductors SI and 22 are adapted to term the respective conductors 01'. a string 01' parallel connected Christmas tree lights. In the screw shell 28 is threaded a disk 24 of insulating material which has a rectangular or other non-circular opening 25 at the center arranged above the center terminal 20 of the base. This socket is adapted tor use with a plug 48 having "threaded into the screw shell.

a center contact 41 which non-rotatably flts within the opening 44. With this arrangement the disk 24 is threaded into and out o! the shell 24 by the plug.

Before inserting the plug in the socket, disk 24 occupies the position shown in Fig. 8. When the plug is first inserted inthe socket, the center contact 31 enters the opening I! and as the plug is threaded into the socket, the disk 34 moves with the plug to the position shown in Fig. 7. In this position the center contact of the plug makes contact with the center terminal of the socket. when the plug is unthreaded from the socket, the disk 44 is unthreaded to the position shown in Fig. 8; It is not threaded beyond this position since the threads or the plug are then clear or the threads of the shell.

The socket shown in Figs. 10 and i1 is identical in construction with the socket shown in Figs. '7, 8 and 9 except for the arrangement for preventing short-circuits between the terminals or the socket. In this socket a disk 38 of insulating material is loosely carried within the shell 28 by a spring 40. The spring is suitably secured at the bottom of the socket and is fastened to the disk 44 by an inwardly rolledflange 40 on the edge of the disk. The spring 39 normally moves the disk 48 to the position shown in Fig. 11. In this position a contact 4| carried by the disk is spaced from the center terminal 30 oi the socket thereby preventing short-circuits between the terminals of the socket. When a plug 42 is threaded into the base, the spring 39 is compressed and the disk 34 is moved to the position shown in Fig. '1 in which the contact 4| makes contact with the center terminal of the socket. In this position the contact 4i becomes in eflect the center terminal of the socket. This socket may be used with standard plugs.

The modification shown in Figs. 12 and 13 is similar to the socket shown in Figs. 1 to 4 inclusive. This modification has a base comprls ing parts 2 and 3 similar to the parts 2 and 3 shown in Figs. 1 to 4 inclusive which define a recess 42 in which is located a screw shell 43 which serves as one terminal for the socket.

The abutting surfaces or the parts of the base are provided with grooves in which are received a pair of conductors 4. To one of the conductors 4 is connected a contact 44 which projects into the recess 42 through an opening formed by complementary grooves in the abutting suriaces oi the parts of the base. The contact 44 serves as the center terminal of the socket. To the other of the conductors 8 is secured a contact 45 which likewise projects into the recess 42 through an opening formed by complementary grooves in the abutting surfaces of the parts of the base. The part of the contact 4' within the recess 42 is provided with a resilient flange 48 which is spaced from the bottom of the recess.

Thgscrew shell is provided with a helical flange 41 which fits in screw threads 48 in the base. The friction between the flange 41 and the threads 48 is less than the friction between the threads 49 in the screw shell and the threads 50 on a plug 5| When the plug is unthreaded from the screw shell, the screw shell will be moved to its outer position shown in Fig. 13 in which further movement of the shell is stopped by the engagement of the flange 41 with the end of the threads 48. In this position, there is a wedging action between the flange 41 and the threads 44 which tends to separate the parts areas 2 and I of the base. From one aspect, the'end oi the threads I forms a stop for preventing outward movement of the shell. The pressure exerted on the flange 41 by the parts of the base tends to hold the screw shell in its outer position so that it will not be moved inward by jarring the socket.

At the lower end of the screw shell is a disk 52 of insulating material which is held in place by spinning the lower end of the screw shell. The disk 52 has a rivet 53 at its center the upper end oi which is adapted to engage the center contact M or the plug II and the lower end of which is adapted to engage the center terminal 4| oi the socket.

When the socket is empty, the screw shell 43 will be in its outer position as shown in Fig. 13. In the use oi the socket, a plug ii is threaded into the screw shell. The threading of the plug into the screw shell continues until the friction between thethreads 4! and BI is greater than the friction between the flange 41 and the threads 48. At this time, further turning oi' the plug causes the screw shell to be threaded into the base until the rivet Bl engages the terminal 44 and the flange ii on the screw shell engages the flange 48 on contact 15. The resilience of flange l8 insures good contact between the contact II and the screw shell. Further turning of the plug causes the plug to be threaded into the shell until the center contact II 01' the plug engages the rivet 53 and completes the electric circuit to the plug.

When the plug is unthreaded from the socket, the screw shell is first moved to its outer position shown in Fig. 13 since the friction between the flange ll and the threads 48 is less than the friction between the threads 49 and 50. In this position, the screw shell and the rivet 53 are electrically disconnected from the contacts 44 and I and the socket cannot be short circuited by bits of tinfoil or other conducting material which may fall into the screw shell. After the screw shell reaches its outer position, further turning of the plug causes the plug to be unthreaded from the shell. One advantage of this socket over the socket shown in Figs. 1 to 4 inclusive is that the disk 52 and the rivet 53 close the bottom of the screw shell and completely protects the contacts 44 and 45 from short circuit when the socket is empty.

What I claim as new and desire to secure by Letters Patent of the United States is:

'1. In an electric socket, a base having a center terminal and a screw shell being adapted to recelve a plug having contacts for co-operating with said center terminal and screw shell, a disk of insulating material above said center terminal, said disk being threaded in said shell, means adapted to cooperate with a part of the plug whereby threading the plug out of said shell moves said disk away from said center terminal to a position protecting said terminal from shortcircuiting.

2. In an electric socket, a base having a center terminal and a screw shelL'a disk of insulating material threaded into said shell, and an opening in said disk into which the center contact of a plug may project, said opening and said center contact being shaped so that said disk is threaded into and out of said shell with said plug.

3. In an electric socket, a base of insulating material having threaded side walls, a center terminal, for co-operating with the center contact of a plug to be inserted in said socket, a screw shell threaded in said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with the plug threaded in the shell, means limiting the outward movement 0! the shell prior to disengagement of said threads whereby rotation 01' the shell in the base is stopped so that the plug may be unthreaded therefrom, and a contact in the base engaged by the shell when the shell is threaded into the base, said contact being spaced from theshell when the shell is threaded out of the base.

4. In an electric socket, a base of insulating material having threaded side walls, a center terminal. for co-operatlng with the center contact of a plug to be inserted in said socket, a screw shell threaded in said base; the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out or the base with the plug threaded in the shell, the threads of the shell and the base being such that the shell cannot be completely threaded out of the base. and a contact in the base engaged by the shell when the shell is threaded into the base, said contact being spaced from the shell when the shell is threaded out of the base.

5. In an electric socket, a base of insulating material having threaded side walls, a center terminal, for co-operating with the center contact of a plug to be inserted in said socket, a screw shell threaded in said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with the plug threaded in the shell, stops on said base arranged to engage the shell for limiting the outward movement of the shell prior to disengagement of said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded therefrom, and a contact in the base engaged by the shell when the shell is threaded into the base. said contact being spaced from the shell when the shell is threaded out of the base.

6. In an electric socket, a base having threads in the side walls at the top and a recess below said threads, a screw shell threaded in said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with a plug threaded in the shell, projections on said shell extending in said recess for limiting the outward movement of the shell prior to disengagement of said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded therefrom, and a contact in the base engaged by the shell when the shell is threaded into the base. said contact being spaced from the shell when the shell is threaded out of the base.

7. In an electric socket, a base of insulating material having threaded side walls, and a center terminal, a screw shell threaded into said base. the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with a plug threaded in the shell, a member of insulating material carried by the shell and having provisions for eflecting contact of the center contact of said plug with the center terminal of the socket when said member is in its inner position, means limiting the outward movement of the shell prior to disengagement of .said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded thereirom, and a contact in the base engaged by the shell when the shell is threaded into the base, said contact being spaced irom the shell when the shell is threaded out of the base.

8. In an electric socket, a base of insulating material having threaded side walls, a center terminal, a screw shell threaded into said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with a plug threaded in the shell, a member of insulating material carried by the shell for preventing short-circuit of the socket, said member having provisions for effecting contact of the center contact of said plug with the center terminal of the socket when said member is in its inner position, and means limiting the outward movement of the shell prior to disengagement of said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreadcd therefrom.

9. In an electric socket a screw shell, a base split along the axis of the shell, a U-shaped wire clip having arms extending axially along the base and being adapted to resiliently hold the parts of the base together, and an extension of one of the arms of the clip providing a clip for gripping a support between it and the base.

10. In an electric socket, a screw shell, a base split along the axis of the shell, spaced grooves in the abutting surface of one of the parts of the base for clamping a pair of conductors between the parts of the base, a pair of contacts each having tangs fitting over one of the said conductors. said contacts being respectively electrically connected to one and the other of said conductors by squeezing said tangs, the'tangs of one of said contacts enclosing the other of said conductors, and means whereby one of said contacts is adapted to engage said shell.

11. In an electric socket, a base of insulating material having threaded side walls, a center terminal, a screw shell threaded into said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out of the base with a plug threaded into the shell, a member of insulating material at the bottom of the shell for preventing short circuit of the socket when the screw shell is in the outer position, and means for limiting the outward movement of the-shell prior to disengagement of said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded therefrom.

12. In an electric socket, a baseoi' insulating material having threaded side walls, a center terminal, for co-operating with the center contact of a plug to be inserted in said socket, a screw shell threaded into said base, the friction between the threads of the shell and the threads of the base being such that the shell is threaded into and out 0! the base with the plug threaded into the shell, stops on said base, arranged to engage the shell for limiting the outward movement of the shell prior to disengagement of said threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded therefrom.

13. In an electric socket, a screw shell, a basesplit along the axis of the shell, spaced grooves in the abutting surface of one of the parts 01' the base for clamping a pair 01' conductors be- Y tween the parts of the base, a pair of contacts respectively connected to one and the'other of said conductors, arms on one of .said contacts holding both of said conductors in spaced relation, and means for holding the parts of the base together.

14. In an electric socket, a base having a center terminal and a screw shell threaded into said base, the frictionbetween the threads of the shell and the threads on the base being such that the shell is threaded into and out of the base with a plug threaded in the shell, a member of insulating material carried by the shell for preventing short circuit of the socket, said member having a contact extending through the center and adapted to make contact with the center terminal of the socket and with the center contact oi a plug threaded in the shell, said contact being spaced from the center terminal when the shell is threaded out of the base, and means for limiting the outward movement of the shell.

15. In an electric socket, a screw shell, a base split along the axis of he shell, spaced grooves in at least one of the butting surfaces of the parts of the base for clamping a pair of conductors between the parts of the base, a pair of contacts respectively connected to one and the other of said conductors, one of said contacts serving as the center terminal of the socket, and the other of said contacts contacting the shell, and grooves formed in at least one of the abutting surfaces of the parts of the base for holding said contacts in place.

16. In an electric socket, a base having a center terminal for co-operating with the center contact of a plug to be inserted in said socket, a

the threads and said flange being such that the shell is threaded into and out of the base with the plug threaded in the shell, means including said flange for limiting the outward movement of the shell prior to disengagement of said flange and threads whereby rotation of the shell in the base is stopped so that the plug may be unthreaded therefrom, and a contact in the base engaged by the shell when the shell is threaded into the base, said contact being spaced from the shell when the shell is threaded out of the base.

17. In an electric socket, a base having a center terminal and a screw shell threaded into said base, the friction between the threads of the shell and the threads on the base being such that the shell is threaded into and out of the base with a plug threaded in the shell, a member of insulating material carried by the shell for preventing short circuit of the socket, said member having a contact extending through the center and adapted to make contact with the center terminal of the socket and with the center contact of a plug threaded in the shell, said contact being spaced from the center terminal when the shell is threaded out o! the base, means for limiting the outward movement of the shell, and a contact in the base engaged by the shell when the shell is threaded into the base, said contact being spaced from.

greases threaded therein and in its outer position pieventing contact oi! said center terminals and pro- 19. In an electric socket, a base having a center terminal and a screw shell. said base being split Patent No. 2,158,8h8.

along the axis or the shell and having threads therein cooperating with threads on the screw shell, the iriction between said threads being such that the shell is threaded into and out 01 the base with a plug threaded into the shell, a spring clip for holding the parts oi the base together, the threads on the base'and the screw shell being formed so that the screw shell can not be completely threaded out oi the base. and a part of the threads cooperating with the shell to have a. wedging action tending to separate the partsotthebasewhenthescrewshellisinits outer position whereby the screw shell will be ipped between the parts of the base and securely held in its outer position.

20, In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw shell, the friction between said threads being such that the shell is threaded into and out of the base with a plug threaded into the shell, is spring clip for holding the parts of the base together, and co-operating parts on the shell and the base having a wedging action tending to separate the parts of the base when the screw shell is in its outer position whereby the screw shell will be i ped between the parts oi the base and securely held in its outer position.

21. In an electric socket, abase having a center terminal and a screw shell, said base being split alongtheaxisottheshellandhavingthreads therein cooperating with threads on the screw shell, the friction between said threads being such that the shell isthreaded into and out of the base with a plug threaded into the shell, means for holding the parts of the base together, the threads on the base and the screw shell. being formed so that the screw shell can not be completely threaded out 01' the base, and a part of the threads cooperating with the shell to have a wedging action tending to separate the parts of the base when the screw shell is in its outer position whereby the screw shell will be r pped between the parts 01 the base and securely held in its outer position.

22. In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw shell, the irlction between said threads being such that the shell is threaded into and out of the base with a plug threaded into the shell, means for holding the parts of the base together, and cooperating parts on the shell and the base having a. wedging action tending to separate the parts 0! the base when the screw shell is in its outer position whereby the screw shell will be gripped between the parts 01 the base and securely held in its outer position. I

23. In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw GEORGE n. BENANDER.

CERTIFICATE OF CORRECTION.

' Play 16,. 19 9.

GEORGE B. BENANDER.

It is hereby certified that error appears in the printpd specification of the above numbered patent requiring correctionas follows: Page 1, sec- 0nd column, line 52, for "thrads" read threads page 5, first column, line 75, and second column, lines li and 29, and page l first column, 'line 55, claims 5, i 5 and 12 respectively, after the word "terminal" strike out the comma; and that the said Letters Patent should be read with this correction therein that the same may conform to the record ofthe case in the Patent Office;

Signed and sealed this hth day of July, A. l). 1959.

Henry Van Arsdale (8 acting Comissioner of Patents.

greases threaded therein and in its outer position pieventing contact oi! said center terminals and pro- 19. In an electric socket, a base having a center terminal and a screw shell. said base being split Patent No. 2,158,8h8.

along the axis or the shell and having threads therein cooperating with threads on the screw shell, the iriction between said threads being such that the shell is threaded into and out 01 the base with a plug threaded into the shell, a spring clip for holding the parts oi the base together, the threads on the base'and the screw shell being formed so that the screw shell can not be completely threaded out oi the base. and a part of the threads cooperating with the shell to have a. wedging action tending to separate the partsotthebasewhenthescrewshellisinits outer position whereby the screw shell will be ipped between the parts of the base and securely held in its outer position.

20, In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw shell, the friction between said threads being such that the shell is threaded into and out of the base with a plug threaded into the shell, is spring clip for holding the parts of the base together, and co-operating parts on the shell and the base having a wedging action tending to separate the parts of the base when the screw shell is in its outer position whereby the screw shell will be i ped between the parts oi the base and securely held in its outer position.

21. In an electric socket, abase having a center terminal and a screw shell, said base being split alongtheaxisottheshellandhavingthreads therein cooperating with threads on the screw shell, the friction between said threads being such that the shell isthreaded into and out of the base with a plug threaded into the shell, means for holding the parts of the base together, the threads on the base and the screw shell. being formed so that the screw shell can not be completely threaded out 01' the base, and a part of the threads cooperating with the shell to have a wedging action tending to separate the parts of the base when the screw shell is in its outer position whereby the screw shell will be r pped between the parts 01 the base and securely held in its outer position.

22. In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw shell, the irlction between said threads being such that the shell is threaded into and out of the base with a plug threaded into the shell, means for holding the parts of the base together, and cooperating parts on the shell and the base having a. wedging action tending to separate the parts 0! the base when the screw shell is in its outer position whereby the screw shell will be gripped between the parts 01 the base and securely held in its outer position. I

23. In an electric socket, a base having a center terminal and a screw shell, said base being split along the axis of the shell and having threads therein cooperating with threads on the screw GEORGE n. BENANDER.

CERTIFICATE OF CORRECTION.

' Play 16,. 19 9.

GEORGE B. BENANDER.

It is hereby certified that error appears in the printpd specification of the above numbered patent requiring correctionas follows: Page 1, sec- 0nd column, line 52, for "thrads" read threads page 5, first column, line 75, and second column, lines li and 29, and page l first column, 'line 55, claims 5, i 5 and 12 respectively, after the word "terminal" strike out the comma; and that the said Letters Patent should be read with this correction therein that the same may conform to the record ofthe case in the Patent Office;

Signed and sealed this hth day of July, A. l). 1959.

Henry Van Arsdale (8 acting Comissioner of Patents. 

